Reinforced corrugated sheet



y 1939- H. W.-ROMANOFF in 2,160,677

REINFORCED CORRUGATED SHEET Filed Sept. 15, 1937 H/PPOL YTE WROMAA/OFFINVENTOR BY RM ATI'ORNEY Patented May 30, 1939 UNITED STATES PATENTOFFICE REINFORCED CORRUGATED SHEET Hlppolyte W. Romanofl, New York, N.Y.

Application September 15, 1937, Serial No. 163,886

3 Claims.

My invention relates to reinforced corrugated sheets and has particularreference to corrugated metal or paper sheets.

Ordinary corrugated sheets have relatively low resistance againstcrushing, especially if the corrugations are deep and have more or lessflat sides which readily buckle under load. My invention has for itsobject therefore to reinforce the side walls of the corrugations byproviding them with additional or transverse corrugations extending atright angles to the main or longitudinal corrugations. The transversecorrugations impart rigidity to the walls of the main corrugations andstrengthen them against collapsing under load so l5 that my corrugatedsheets can withstand greater loads without collapsing than ordinarycorrugated sheets. advantageously used for making cardboard boxes of arelatively high rigidity, sound and heat insulatingboards and similararticles.

My invention is more fully described in the accompanying specificationand drawing in which Fig. 1 is a. perspective view of my corrugatedsheet, and

Fig. 2 is a perspective view of another form of my corrugated sheet.

My reinforced corrugated sheet I comprises main or longitudinalcorrugations 2 which may be of a trapezoidal shape as shown in Fig. 1 orrounded as shown in Fig. 2. The side walls 3 of the main corrugationsare themselves corrugated, having relatively small transversecorrugations 4 extending at right angles to the longitudinalcorrugations. These transverse or secondary corrugations may be of anysuitable shape.

These secondary corrugations represent reinforcement of the side wallsof the main corrugations and prevent or inhibit their buckling underload. The top surfaces of the corrugations may Such doubly corrugatedsheets can be be fiat as shown in Fig. 1 for gluing them to sheets offlat board or paper when preparing built-up boards.

The sheet of Fig. 2 has round corrugations 5 with small transversestifiening corrugations 6 5 formed in the fiat portions of the sides ofthe longitudinal corrugations and partly extending into the curved topportions.

My doubly corrugated sheets can be also used as a building materialbecause of their considerable l0 rigidity. When applied to sheet metal,the double corrugations render this material suitable for fireproofstructures, such as metal garages, storerooms,warehouses, workshops,etc.

I cla m as my invention: 15

1. A reinforced corrugated sheet with corrugations of a trapezoidalcross-section, having top and bottom planar portions lying in twoparallel planes, the side walls having straight transverse corrugationseoterminous with the said planar 20 portions thereby imparting a zig-zagoutline to the edges of the planar portion.

2. A reinforced corrugated sheet with corrugations having straight sidewalls and planar top and bottom portions lying in two parallel planes, 5the wallshaving transverse corrugations of a. zig-zag shape coterminouswith the said planar portions.

3. A reinforced corrugated sheet with corrugatlons having side walls andtop and bottom 30 planar portions lying in two parallel planes, thewalls having transverse corrugations coterminous with said planarportions thereby imparting an outline to the edges of the planarportions corresponding to the cross-sectional outline of the 35corrugations and thereby rendering inflexible the joints between thewalls and planar portions.

HIPPOLYTE W. ROMANOFF.

